#librsync #rsync #delta #signature #calculate #access #system

librsyncr

librsyncr is a Rust library to calculate and apply deltas between two files without having access to both files on the same system

2 releases

0.1.1 Oct 30, 2019
0.1.0 Oct 22, 2019

#12 in #rsync

MPL-2.0 license

35KB
677 lines

librsyncr

Crates.io

Documentation

librsyncr is a Rust library to calculate differences between two files without having access to both files on the same system. It is a rewrite of the librsync C library (without looking at the librsync source code), and the signature and delta files are compatible with that library. The C library is 3562 lines of C (not including comments or vendored Blake2 and MD4 code), but this library is only 753.

strong_hash Feature

The default hash used for looking up blocks from a signature file is not resistant to hash DoS attacks. If you are using this library in a web service to process untrusted signature files, you will likely want to enable the strong_hash feature.

Performance

Testing with Wikiquote dump files (about 38 MB) on a Intel Core-i7-6700K 4.0 GHz processor:

# this library
./target/release/examples/rdiff signature ./enwikiquote-20170501-abstract.xml ./enwikiquote-20170501-abstract-sig.xml

85ms (447 MB/s)

# librsync
./rdiff signature ./enwikiquote-20170501-abstract.xml ./enwikiquote-20170501-abstract-sig.xml

77ms (494 MB/s)


# this library
./target/release/examples/rdiff delta ./enwikiquote-20170501-abstract-sig.xml ./enwikiquote-20170701-abstract.xml ./enwikiquote-delta.xml

115ms (330 MB/s)

# librsync
./rdiff delta ./enwikiquote-20170501-abstract-sig.xml ./enwikiquote-20170701-abstract.xml ./enwikiquote-delta.xml

118ms (322 MB/s)


# this library
./target/release/examples/rdiff patch ./enwikiquote-20170501-abstract.xml ./enwikiquote-delta.xml ./enwikiquote-new.xml

67ms (567 MB/s)

# librsync
./rdiff patch ./enwikiquote-20170501-abstract.xml ./enwikiquote-delta.xml ./enwikiquote-new.xml

24ms (1583 MB/s)

File formats

The C librsync library has documentation on the signature file format, and the .NET librsync library has documentation on the delta file format.

License

Licensed under the Mozilla Public License Version 2.0.

Dependencies

~280KB